Feeding device for stokers



Feb.20, 1934. w. D. BURTON FEEDING DEVICE FOR STOKERS Filed Sept. 6, I930 151106117161: wanren/ D. Bwriw,

Patented Feb. 20, 1934 FEEDING DEVICE FOR STOKEBS Wan-en D. Burton, Goshe'mlnd assignor to Combustioneer, Inc., Goshen, ImL, a corporation of Illinois Application September a, 1930. Serial No. 480,077 is (Emmet-101.25%)

The present invention relates to improvements in feeding devices for stokers, and particularly stokers in which fuel is automatically supplied from a hopper.

Coarse dry fuel is brought down readily in i the hopper to the discharge opening. However,

finely comminuted fuel, particularly when wet,

, tends to pack and bank, and will arch over the feeding mechanism. Partial agitation will not 1 bring down the fuel, but will only cut a swath in the mass without dislodg'ing the rest. Obviously, failure of the fuel to feed uniformly from the hopper is highly objectionable.

Various important objects of the invention therefore reside in the provision of a novel agitator for fuel feeding hoppers which is capable of reaching practically every part of the mass of fuel so as to thoroughly dislodge any fuel tending to pack, which will be, effective regard- 0 less of whatever position it may occupy when the hopper is filled, and which does not require ,an excessive amount of power.

Other objects of the invention are to provide a new and improved a'gitator which will tend upon movement through its orbit to dig into the fuel mass, and which in general is eflicient in operation and simple and inexpensive in construction. I

Further objects and advantages will'become apparent as the description proceeds.

In the accompanying drawing, Figure 1 is a plan view of a feeding device embodying the features of my invention.

Fig. 2 is a vertical sectional view taken along 85 line 22 of Fig. 1.

Fig. 3 is a fragmentary vertical sectional view taken along line 3-3 of Fig. 2. i

Fig. 4 is a view similar to Fig. 2 of a modified form of the invention. Fig. 5 is a fragmentary sectional view taken along line 5--5 of Fig. 4. While the invention is susceptible of various modifications and alternative constructions, I have shown in the drawing and will herein describe in detail the preferred embodiment, but

it is to be understood that I do not thereby intend to limit the invention to the specific form disclosed, but intend to cover all modifications and alternative constructions falling within the spirit and scope of the invention as expressed in the appended claims.

Referring more particularly to the drawing, the invention is adapted for various types of stokers comprising feed hoppers, and for purposes of illustration is described in connection with 'a vertical hopper 10 having a conveyor screw 11 extending laterally through the bottom for discharging the fuel from one side thereof. Preferably, the hopper 10 is rectangular in horizontal cross-section, and comprises a base 12 having inclined side walls 13 and 14 defining a V-shaped trough 15, and end walls 16 and 17 respectively inclined and vertical.

The upper portion of the hopper 10 comprises three downwardly and inwardly inclined walls 18, 19 and 20 and a vertical wall 21 defining a downwardly constricted space 22 opening to the top of the base 12. Three downwardly and outwardly inclined walls 23, 24 and 25 and a vertical wall 26 are joined respectively to the upper edges of the walls 18 to 21, and define a downwardly expanded space 27 constituting an upward continuation of the space 22.

The conveyor screw 11 extends along the trough 15 and into a discharge duct 28 opening from the interior of the base 12 through the end wall 17, and comprises a helical blade 29 and an axial drive shaft 30. One end of the shaft 30 extends through the wall 16 for connectio to a suitable driving mechanism 31.

The agitator comprises a worm gear, preferably in the form of a star wheel 32, comprising a plurality of radial arms 33 meshing with the helical blade 29 of the screw conveyor 11. While the star wheel 32 may be mounted inany suitable position relative to the screw conveyor 11, it is disposed horizontally at one side thereof, and is rotatably mounted on a vertical stud 34 in the bottom of the hopper base 12. Preferably, the base 12 is enlarged at one side as indicated at 35 to define a space 36 adapted to accommodate the star wheel 32 and the parts attached thereto.

An upstanding post or bracket 37 is formed on one of the arms 33 in eccentric relation to the stud 34. Pivotally secured to the upper endof the post 37 is an agitator arm 38. In the form shown in Figs. 1 to 3, one end of the arm 38 is formed with an eye 39 secured against the inner side of the post 3'? by means of a pivot bolt 40.

The arm 38 is bent upwardly intermediate its lug 43 is effective to'prevent movement of the arm 38 beyond vertical center as shown in dotted 0 outline in Fig. 2. A spring 44 coiled about the pivot 40 and anchored at o e end to the post 37,

- the arm 38 will move outwardly under the influence of the spring 44. Thus, the arm is caused to reach practically all parts of the fuel, including that in the corners of the hopper. Consequently, the fuel cannot arch in the upper portion of the hopper l0, but .is supplied as required to the conveyor 11.

The modified form shown in Fig. 4-is generally similar to that of Figs. 1 to 3, and hence corresponding parts of the two forms are identified by like reference characters. In the modified form, the eye 39 on the end of the arm 38 is secured to the post 37 by means of a clevis 45 so as to provide a universal connection. The arm 38 is bent substantially at right angles adjacent the eye 39 as indicated at 46, and hence is movable against the post 3'7 which thus constitutes a stop for limiting the upward movement of the arm. Secured to the free end of the arm 38 and extending longitudinally thereof is a blade or plow 47 adapted to'cut into the fuel mass. A weight 48 is provided on the free end of the arm 38 and preferably is formed with an' edge 49 in alinement with that of the blade 47 to improve the cutting action.

The operation is generally the same as that of the first form. The arm 38 turns on its own axis as well as that of the clevis 45, thus having a gyratory motion, and cuts a core of gradually increasing size in the fuel. The weight 48 causes the blade 47 to follow and cut into the receding surface of the fuel. A thorough agitation of the fuel including that in the corners is thus accom= plished.

I claim as my invention:---

1. In a stoker, in combination, a hopper, a conveyor screw in the bottom of said hopper, a star wheel disposed on a vertical axis at the bottom of the hopper in mesh with said screw, and an agitating member flexibly connected to said star-wheel and extending upwardly in said hopper, said member being attached to said star wheel for driven orbital movement through said hopper.

2. In a stoker, in combination, a hopper, a conveyor screw in the bottom of said hopper,.a star wheel in mesh with said screw and rotatable about a. vertical axis, a post eccentrically mounted on said star wheel, and an arm mounted on said post for rotation with the star wheel, one end of said arm extending upwardly in said hopper in the general direction of the axis of the star wheel.

3. In a stoker, in combination, a hopper, a conveyor screw in the bottom of said hopper, a star wheel in mesh with said screw; a post eccentrically mounted on said star wheel, an elongated arm bent intermediate its ends and having an eye on one end pivotally secured to one side of said post, the free end of said arm extending upwardly in said hopper, a pair of spaced lugs on said post at opposite sides of said am for limiting the pivotal movement of said arm,

and spring means tending to move said downwardly andoutwardly against one of said lugs. I

4. In a stoker, in combination, a hopper, a conveyor in the bottom of said hopper, a star wheel operatively connected'to said conveyor, 2. post eccentrically mounted on said star wheel, an elongated arm pivotally secured to one side of said post, the free end of said arm extending upwardly in said hopper, means for limiting the pivotal movement of said arm, and means tending to move said arm outwardly toward .the side of said hopper.

5. In a stoker, in combination, a vertical hopper adapted to contain fuel, a. conveyor screw in the bottom of said hopper, a horizontal star wheel in the bottom of said hopper meshing with one side of the screw, and an agitating arm having a universal eccentric connection with said star wheel and extending upwardly in said hop-- per. 1

6. In a stoker, in combination, a fuel hopper, a rotatable member in said hopper, an agitating arm flexibly connected at one end to said rotatable member and extending freely at the other end in said hopper, and resilient means urging s'aid free end toward a wall of said hopper.

7. In a stoker, in combination, a fuel hopper, a rotatable member in said hopper, an agitating arm flexibly connected at-one end to said rotatable member and extending freely at the other end in said hopper, and a scraper blade with an elongated narrow edge on said am extending longitudinally throughout substantially the length of the arm.

8. In a stoker, in combination, a vertical hopper adapted to contain fuel, a conveyor screw in the bottom of said hopper, a horizontal star wheel meshing with one side of said screw, a vertical post mounted eccentrically on said star wheel, and an arm having a. pivotal connection at one end with said post and extending upwardly in said hopper, said arm being free to move away from said, post into engagement with the side walls of said hopper, said post serving to limit the upward movement of said arm.

9. In a stoker, in combination, a vertical hopper adapted to contain fuel, a conveyor screw in the bottom of said hopper, a horizontal star wheel meshing with one side of said screw, a vertical post mounted eccentrically on said star wheel, an arm having a universal connection at one end with said post and extending upwardly in said hopper, said arm being free to move away from said post into engagement with the side walls of said hopper, said post serving to limit the upward movement of said arm, a longitudinal blade formed along the underside of the free end of said arm and a weight on the free end of said arm, said weight being formed with a 185 cutting edge in alinement with that of said blade.

10. In a stoker, in combination, a hopper adapted to contain fuel, a rotatable element in said hopper, an elongated agitating member connected at one end to said element, the center of gravity of said member being located to one side of said one end, a weight .on the free end of said member, and a longitudinal scraper blade having a narrow edge secured to said member, said blade and weight being so related that said blade cuts through the fuel as said weight pulls the blade into contact therewith. 11. In a stoker, in combination, a vertical hopper adapted to contain fuel, a conveyor screw in the bottom of said hopper, a star wheel in H0 the bottom of said hopper meshing with one side of said screw, an agitating arm flexibly connected at one end to said star wheel and extending upwardly in said hopper, a weight on the free end of said arm,,and a longitudinal blade secured to the underside of said arm.

12. In a stoker, in combination, a vertical hopper adapted to contain fuel, a conveyor screw in the bottom of said hopper, a star Wheel in the bottom of said hopper-meshing with one side 01' the screw, an agitating arm fixedly connected at one end to said star wheel and extending upwardly in said hopper, and a weight on the free end of said am, said weight being formed with a cutting edge. 1

13. In a stoker, in combination, a fuel hopper, a rotatable member in said hopper, an agitating arm having a flexible connection at one end with said rotatable member and extending freely upwardly at the other end in said hopper, the center of gravity 01 said arm being located to one side of said connection, and a weight of substantial mass on the free end of aid arm arranged to exert a force by gravity on said arm for moving the free end of said arm outwardly of said connection toward the walls of said hopper in the operation of the mechanism.

WARREN D. BURTON.

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